The Research On Heat Analysis And Flow Field Characteristics Of Cryogenic Control Valve For20K

In recent years, the government has approved and constructed a number of majorscientific research projects, most of which must rely on large cryogenic refrigerationsystems to provide a cold source. The cryogenic control valves are the necessarycomponent in the large cryogenic refrigeration systems for effective controlling and playan irreplaceable role. It will have a direct impact on large cryogenic refrigeration systems’safe and reliable operation and promotion of performance. And there aren’t any cryogeniccontrol valves applying to the liquid hydrogen and the following temperature range.This article makes an in-depth study on performance of cryogenic control valve fromthe internal flow and thermal analysis. The main contents are as follows:1.Based on the fluid mechanics theory, Using computational fluid dynamics softwareFluent, steady internal flow characteristics of each opening of the control valve aresimulated, and helium is set as the fluid medium in the simulations. The unsteadyprocesses of the control valves’ opening and closing are also simulated and analyzed, withthe help of the dynamic grid technology. Then, the changing curves of flow over time aregained. And the impacts on flow of valves’ opening and closing speed are analyzed.2. The pathways of heat leakage in the cryogenic control valve under the actualconditions are analyzed based on the related heat transfer theory. And the theoretical heatleakage is calculated. Several projects about reducing the heat leakage in the cryogeniccontrol valve are proposed, against to the pathways of heat leakage of cryogenic controlvalve. The steady and dynamic heat transfer processes are simulated by the finite elementanalysis software ANSYS. At last, the thermal expansion of the heat sink is discussed.